Furnace for heating rock drills and rock-drill steel



July 7, 1925. 1,544,581

5. HOSKEN FURNACE FOR HEATING ROCK mums AND ROCK 1mm, STEEL Filed Jan.'12, 1924 5 Sheets-Sheet 1 July 7, 1925. I 1,544,581-

s. HOSKEN FURNACE F 0R HEATING ROCK DRILLS AND ROCK DRILL STEEL FiledJan. 12, 1924 5 Sheets-Sheet 2 July 7, 1925.

s. HOSKEN FURNACE FOR HEATING ROCK DRILLS AND ROCK DRIL Filed Jan. 12,1924 L STEEL 5 Sheets-Sheet 5 1,544,581 S. HOSKEN Filed Jan. 12, 1924' 5Sheets-Sheet 4 FURNACE FOR HEATING ROCK DRILLS AND ROCK DRILL STEEL July7, 1925.

July 7 1925.

s. HOSKEN FURNACE FOR HEATING ROCK DRILLS AND ROCK DRILL STEEL 11m Jan.12, 1924 s Sheets-Sheet 5 :srATE s omen. 1

Patented July 7, 1925.

r A SAMUEL nosxnm or .JOHANNESBUBQ)IRANSVAAL, SOUTH AFRICA.

I FURNACE FOR HEVATINGROCK nRILLs un ROCK-DRILL STEEL.

Application filed ianuar y 12, 19 2 4. Serial No. es5,s4s'.

T0 allwhomz'tmag/ concern: V

Be it known that LSAMUEL HosK-nN, a subject of the King of GreatBritain,and resident of Johannesburg, TransvaalProvince, Union'of South Africa,have invented a certain new and useful Improvement. in Furnaces forHeating Rock Drills and Rock-Drill Steel, of wl iclrthefollowing isaspecification. f 5 A h This invention has reference to furnacesparticularly designed for and especially applicable for heating bars ofsteel which are to be forged or formed into rook drills,,.or rockdrilling machine bits, and for heating s'uch drills, bits or the likepreparatory to I certain of the. carrylng means omitted.

re-sharpening the same and also for heating such drills or bits for thepurpose of hardening'the Cutting ends ant shanks thereof.

One object of the present invention is to devise an .ele'ctrical furnacein which }the drill or; drill steel can be heated gradually, or instages, to any desired and predetermined maximum temperature.

1 A further object is to ensure thatthe drill, bit, etcetera, shall passcontinuously'through all the stages of the heating process in apredetermined period'or length of time. v

still further object'of the invention is tog ensure thatthedrillor drillsteel shall net-itewithdrawn from the furnace during its passagefltherethrough.

Q'According to the. invention the furnace is constructed in ordividedinto any desired and su table number of, sect ons, arrangedins'uch a" manner. that the drills, bits, etcetera,j in the heatingprocess, will travel through the section of the furnace of lowesttemperature and continue without stopping through the succeedingsections of gradually rising or higher temperature into the lastsection, which is heated to the desired maximum temperature.

The means which is'provided for carrying or passing the drills, bits,,etcetera, through the several sections ofthe furnace are designed sothat thei. passage of ,the. drills through the furnace takesiplaceduring the predetermined period of-timenecessary to raise the drill-s,etcetera, gradually to the desired maximum temperature, and prefers ablysothat the temperaturev or, the drills is raised to-tlie temperature ofeach section ofthe furnace in their passage through such section. v s

Preferably adjustable-means are provided which prevent withdrawal of thedrill or steel during its passage through the furnace. 7 The inventionwill be fully described with the aid of the accompanying drawingswherein, by way of example,,two embodiments of the invention areillustrated.

In thev drawings,

Fig. 1 isfa side elevation 'of one embodiment ofthe invention, with themeans which carry f the drills through thefurnace removed. 7

F'g. 2 is an end elevation of Fig.1"with tain portions of the carryingmeans.

Fig. 7' is a detail .view of a portion of the heating'chamber of thefurnace illustrating ameans for preventing the withdrawal' of the drillsfrom said chamber at any point intermediate the entrance and exit i IFig. ,8 is a side elevation of the other embodiment of the inventionwith aportion of thei means for carrying the drills omitted, an v [Fig-9is a half-sectional end elevation of the furnaceillustrated in Fig. 8.

j-Referring to the embodiment; of the invention illustratedin Figs. 1 to6 of the drawings, the furnace is soconstructed and arranged that thedrills are passed or car ried through it in a verticalv or uprightposition. In this form of the invention I provide a suitable supportingframework 1 which carries the two plates 2, 3, which form a dividedtableupon which is erected and secured the several sections of theheating chamber or furnace proper. Each section of the arched heatingchamber 4, as shown,

,formed by the two side'bricks or blocks plates 2, 3, of the table.

Each sect-ion of the heating chamber 4 is comprising the two parts 9,10, which are connected together at the top, as indicated at 11," andare hinged at the sides, as indicated at 12 and 13, to the verticalplates 14, 15, which are fixed to the top of the table and extend thefull length of the furnace at.

the outside of the side bricks 5, 6, of all the sections of the furnace.The space between the casing 9, 10, and the bricks 5, 6, 7, may befilled with any. suitable heat non-conducting material.

For the purpose of heating the furnace electrically heating elements 16,17, are shown arranged upon the side bricks or blocks 5, 6, inside thechamber 4, at opposite sides of the opening 8, said elements beingelectrically connected by suitable conductors 1s, 19, 20, 21-, 22. r

The number of sections comprised in the furnace structure andconsequently the aggregate length of the heating chambers provided bythe said sections is designed to accommodate the number of drills, whichit is required to heat in a given period of time, in such a way that thedrills attain the temperature of each section before passing into thenext succeeding section of higher temperature. The temperature gradientor gradually rising temperature of the furnace is obtained by heatingeach-successive section a greater temperature than the preceding sectionfromIthe entrance to the exit.

The means shown for carrying or passing the drills, etcetera, throughthe furnace include a framework 23 connected to the framework'l and tothe part 2 of the table, which framework 23 supports two oval endlesstracks or rails 24,25, one side of each of which tracks is arrangedbeneath the fur nace slightly at one side of the opening 8 7 into theheating chamber 4. The drills 26 areattached to and carried through thefurnace by an endless chain-like structure including links 27 to. whichare attached the carriers 28 which are provided with grooved wheelsorrollers 29, 30-see Figs. 2 to 6 which run on the rails or tracks 24,25, respectively. Each of the carriers 28 is provided at the upper endwith means for attaching thereto the drill 26. The means shown foraccomplishing this includes the formation of .a recess 31 to take thestem of the dri'll26 and a screw 32 which, when screwed in one directionsecures the drill in said recess 31, and in the reverse direction,disconnects the drill and allows it to be removed from the carrier 28.The carrier 28 is shown provided with two rests 33, 34, which arerecessed to take the stem of the drill 26, as shown in Fig. 2, andoperate to steady the. drill'26 and ensure its proper alignment as it isbeing carried through the furnace.

'in' turn driven by a worm wheel 43 off the worm 44 driven by the motor45.

To ensure the drills being placed at the correct height in the carriers28 to pass through the heating chamber 4, a gauge is provided comprisinga plate 46 fixed to the frame 23. In attaching the drills 26 to thecarriers 28 they are placed in the recesses 31 and rests 33, 34, andheld against the underside of the gauge plate 46 while being secured tothe carriers by the screws 32.

The furnace is designed to prevent the withdrawl of the drills in theirpassage therethrough. This object is attained by making width of theopening 8 at the bottom'of the heating chamber 4 of such a width thatthe head or enlarged cutting end of the drill is unable to pass therethrough. If it be desired to make provision for the heating of smallerdrills,-the heads of which would pass'through the opening 8 then thismay. be effected by providing means for altering the width of theopening. Such a means is illustrated in Fig. 7 in which a pair ofeccentrically mounted rods 47, 48, aremounted in brackets 49, 50, and

have levers 51, 52, fixed on their outer'ends for placing and retainingthe eccentric rods 47, 48, in the requisitepositions to givethe desiredwidth of opening between them.

The levers 51, 52 are'provided with, catches V which co-operate withnotched quadrants 53, 54, for retaining the said levers in positionafter the adjustment of the eccentric rods 47, 48.

In the embodiment of the invention illustrated in Figs. 8 and 9, thefurnace is so arranged that the drills are passed through it whilstbeing supported and carried in a horizontal position. In this form thefurnace is constructed to provide the central heating chamber 55, saidchamber being formed between the bricks or blocks 56 arranged in andcarried by the upper portion 57 of the framework and the blocks orbricks 58 arrangedin the lower casing 59 which 'is supported by apedestal 60. The ids of the framing of the upper portion of the furnaceare carried by a suitable frame work or supports 61.

The furnace is provided at both sides with openings 62, 63, leading intothe heating chamber 55 so that two rows of drills can be heatedsimultaneously, two of the carrying means being provided, one at eithersidei ofin'the carriers or rests71 and pushedup the furnace. 62, 63, arethe electrical heating elements. g

The driving arrangements forthe carrying meansin this construction isthe same for both sides of the furnace. and includes two horizontalshafts 64, 65,'through onefof which the motion may beimparted to thecarrying means. These shafts run in intermediate and end bearings 66,67,respectively, the intermediatebearings being carried by the pedestal60, and the end bearings by separate pedestals- 68. On'each of theshafts 64, 65, at both sidesof the furnace there are mounted twosprocket wheels 69, 70.

The carrying means comprises, for each side of the furnace, a pair ofendless chains. One chain engages with the two sprocket wheels 69nearest the side of the furnace, and

the other with the two sprocket wheels 70,

on the outer ends of the shafts 64, 65. The links of the chains areconstructed to form the rests or carriers 71 for the drills 72.

The two chains are connected by. means of rods 7 3 on theouter ends ofwhich there are mounted rollers 74, which are engaged by the teeth ofthe sprocket wheels to operate the chains to convey the drills throughthe furnace. Both ends of the rods 73 are connected by means of smallerlinks 7 5 to impart the requisite rigidity to the carrier structure.

76 are two rails arranged. at either side of the furnace and supportedby the framework 77, in front of the openings 62, 63, through which'thedrills 72 project into the heating chamber-55. Onthese rails 76'therollers 74 of the carrier structure travel as they convey the drillsthrough the furnace. This ensures the drills being maintained in thecorrect horizontal or substantially horizontal position as they passsuccessively through the sections of the furnace of varying temperature.gradually to attain the maximum temperature in the predetermined periodof time, which will depend upon the nature of the steel to be heated. Iv If desiredmeans may be provided for rotating the drill, etcetera, asit is passing through the heating chamber '55. As shown in connectionwith Fig. 8, the rotation of the drill may be effected by providing thedrill carrier 71 with say two rollers 78, one at either side of the rest71, which-rollers will be driven by frictional contact with the rollers74, and by contact withzthe drill 7 2- Which will lie betweenthem-rotate the latter. v

In this embodiment of the invention the gauge or loadingplate 79,whichis in the form of a vertical plate,1 is fixed to the framework andaligned to the centre of the heating chamber 55. As in the previouslydescribed furnace'the drills '72 areplaced to the gauge or loading plate79, and are various sectionsof gradually rising tempera ture, and may beremoved from the carrying. means after they have passed outaof thefurnace or be allowed to fall out: of the rests 71 as the latter passaround the sprocket Wheels at the exit end of the furnace. To ensurethat the drills, shall only be removed from the carrying means afterthey have passed completely through the furnace," the bricks or blocks56, 58 are formed with projections 80 which are arranged at such .adistance apart that ordinarily the head. of thedrill cannot pass out ofthe furnace between said projections. If, however, it be desired to heatdrills having heads of such a size as will pass between the projections80, means, similar to that illustrated in Fig; 7 may be employed toprevent the drills being withdrawn from the furnace during their passagetherethrough. The. furnace according to this invention is capableofheating rock'drills or drill steels of any different ordinary lengths.

' A furnace constructed for the electrical deleterious fumes given offas is the case with furnaces in which fuel is consumed.

'Any suitable electrical control means may be used formaintaining the.desired tempera ture in the various sections or zones of the furnace,and particularly'the maximum or final temperature, according to thegrade or class of steel being heated, thus obviating the possibility ofoverheating or. burning of the steel.

The predeterminedtime periodi necessary for the heating of the drillscan be set and automatically controlled and can be that best suited tothe nature of the steel to be heated. By the adoption of the furnace,once thedrills have been placed in the conveying means,- and in the caseof the verti- .furnace constructed as above described, it

will 'be necessary first, to I determine the period of time that it isnecessary and desirable to take'in heating the drills, or raising themto the desired maximum temperature. This will depend on the carboncontent of the steel and other physical properties thereof, and thespeed at which the conveying means carries the drills through thefurnace is then adjusted or set to ensure that the steel or drill shall"be carried through thefurnacein such period of time. l/Vhat I claim asmy invention and desire to protect by Letters Patent is v 1. Anelectrical furnace for heating rockdrills and rock drill steel,comprising a plurality of independently heated sections providing acontinuous heating chamber of different gradually rising temperaturesfrom one end of the furnace to the other, incombination with mechanicalmeans for continuously conveying the drills or drill steels which are tobe heated through said heating chamber, and means for preventing thewithdrawal of the drills or drill steels from the furnace during theirpassage therethrough, as set forth.

2. An electrical furnace for heating rockdrills and rock drill steel,comprising a plurality of independentlyheated sections providing a.continuous heating chamber of different gradually rising temperaturesfrom one end of the furnace to the other, in combination with mechanicalmeans for continuously conveying the drills or drill steels which are tobe heated through said heating chamber, and adjustable means forpreventing the withdrawal of the drills or drill steels from thefurnaceduring their passage therethrough, as set forth.

3. An electrical furnace for heating rockdrills and rock drill steel,comprising a plurality of independently heated sections providing acontinuous heating" chamber of different gradually rising temperaturesfrom one end of'the furnace to the other, in combination with mechanicalmeans in the form of an endless chain-like structure for continuouslyconveying the drills or drill steels which are to be heated through saidheating chamber, and a guage engaging with that end of the steel whichis to be heated to ensure the drills or drill steels being placed in theconveying means in the correct position to enter the heating chamber, asset forth.

" 4..An electrical furnace for heating rockdrills and rock drill steel,comprising a plurality of independently heated sections providingacontinuous heating chamber of difierent gradually rising temperaturesfrom one end of the furnace to the other, in combination with mechanicalmeans for continuously conveying the drills or drill steels which are tobe heated through said heating chamber, and means for preventing thewithdrawal of the drills or drill steels from the furnace during'theirpassage therethrough, the mechanical means for conveying the drillsbeing in the form of a chain-like structure includingcarriers for thedrills or steels, said carriers having recesses in which the'drills ordrill steels are placedand carried, linkslconnecting said carriers, anda pairof-rollers for each carrier-upon which said carriers are mounted,rails upon which said rollers are adapted to travel and driving meansfor the chain-like structure, said driving means including. rollersmounted on the carriers and a-driving sprocket wheel adapted to engagesaid rollers to movethe chain-like structure as set forth.

5. An electrical furnace for heating rockdrillsand rock drill steel,comprising a plurality of independently heated sections providing acontinuous heating chamber of different gradually rising temperaturesfrom one end of the furnace to the other, in combination with mechanicalmeans for continuously conveying the drills or drill steels which are tobe heated through said heating chamber, means for preventing thewithdrawal of the drills or drill steels from the furnace during theirpassage, therethrough, andmeans for rotating the drills or drill steelsduring their passage through the chamber, the mechanical means forconveying the drills or drill steels .being in the form of a chain-likestructure including carriers for the drills or steels, said carriershaving recesses in whichthe drills or steels are placed and carried,links connecting said carriers, a pair of rollers for each carrier uponwhich said carriers are mounted, rails upon which said rollers areadapted to travel, and driving means for the chain-likestruc- .ture,said driving means including rollers mounted on the carriers and adriving sprocket wheel adapted to engage said rollers to-movethechain-like structure, and the means for .rotating'the drills or drillsteels during their passage through the chamber being in the form ofrollers mounted upon the carriers and running in contact with thefirst-mentioned rollers and the drills or drill steels, as set forth. 7

6. A furnace of the nature indicated comprising a plurality of sectionsproviding a continuous heating chamber of different gradually risingtemperatures in combination with means for conveying the steel articleswhich are to be heated through said heating chamber and means forvarying the width of the. opening into the heating chamber to preventwithdrawal of the steel articles during their passage through theheating chamber, as set forth.

7. A furnace of the nature indicated comprising a plurality of sectionsproviding a continuous heating chamber of different gradually risingtemperatures, in combination with means for conveying the steel articleswhich are to. be heated throughsaid heatingchamber and means forgvaryingthe Width of the opening into the heating chamber to prevent Withdrawalof the steel artioles during their passage through the heating chamber,said means including eccentrically mounted rods and levers for rotatingsaid rods, as set forth.

In testimony whereof I have signed my name to this specifieation in thepresence of two subscribing Witnesses SAMUEL HOSKEN.

\Vitnesses:

G. A. VVEBB,

CHAS. OVENDALE.

